EP1894983A1 - Granules pour l'utilisation dans les productions des outils abrasifs ou coupants - Google Patents

Granules pour l'utilisation dans les productions des outils abrasifs ou coupants Download PDF

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Publication number
EP1894983A1
EP1894983A1 EP06119978A EP06119978A EP1894983A1 EP 1894983 A1 EP1894983 A1 EP 1894983A1 EP 06119978 A EP06119978 A EP 06119978A EP 06119978 A EP06119978 A EP 06119978A EP 1894983 A1 EP1894983 A1 EP 1894983A1
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EP
European Patent Office
Prior art keywords
binding agent
particles
solvent
granule
sinterable
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP06119978A
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German (de)
English (en)
Inventor
Cedric Sheridan
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Individual
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Priority to EP06119978A priority Critical patent/EP1894983A1/fr
Priority to CA2660803A priority patent/CA2660803C/fr
Priority to AU2007291207A priority patent/AU2007291207B2/en
Priority to US12/377,880 priority patent/US20110056143A1/en
Priority to AT07820000T priority patent/ATE467671T1/de
Priority to PCT/EP2007/059103 priority patent/WO2008025838A1/fr
Priority to EP07820000A priority patent/EP2057244B1/fr
Priority to DE602007006512T priority patent/DE602007006512D1/de
Priority to PCT/EP2007/059101 priority patent/WO2008025836A1/fr
Priority to CN200780032031.3A priority patent/CN101511965B/zh
Publication of EP1894983A1 publication Critical patent/EP1894983A1/fr
Withdrawn legal-status Critical Current

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24D—TOOLS FOR GRINDING, BUFFING OR SHARPENING
    • B24D11/00—Constructional features of flexible abrasive materials; Special features in the manufacture of such materials
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24D—TOOLS FOR GRINDING, BUFFING OR SHARPENING
    • B24D18/00—Manufacture of grinding tools or other grinding devices, e.g. wheels, not otherwise provided for
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24D—TOOLS FOR GRINDING, BUFFING OR SHARPENING
    • B24D3/00—Physical features of abrasive bodies, or sheets, e.g. abrasive surfaces of special nature; Abrasive bodies or sheets characterised by their constituents
    • B24D3/34—Physical features of abrasive bodies, or sheets, e.g. abrasive surfaces of special nature; Abrasive bodies or sheets characterised by their constituents characterised by additives enhancing special physical properties, e.g. wear resistance, electric conductivity, self-cleaning properties
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
    • C09K3/00—Materials not provided for elsewhere
    • C09K3/14—Anti-slip materials; Abrasives
    • C09K3/1409—Abrasive particles per se
    • C09K3/1427—Abrasive particles per se obtained by division of a mass agglomerated by melting, at least partially, e.g. with a binder

Definitions

  • the present invention generally relates to articles for use in the field of abrading or cutting tools, in particular to granules comprising abrasive grains surrounded with sinterable material.
  • Tools for cutting and/or abrading are conventionally fabricated of a suitable matrix material with minute abrasive grains, such as diamonds, embedded within the matrix material.
  • a suitable matrix material with minute abrasive grains, such as diamonds, embedded within the matrix material.
  • such tools are formed by conventional powder metallurgical techniques, wherein the abrasive grains are initially mixed with the matrix material (e.g. metals, alloys, metal carbides etc., as well as mixtures thereof) in powder form and some binding agent, after which the mixture press-moulded to bond and shape the mixture into the desired tool.
  • the matrix material e.g. metals, alloys, metal carbides etc., as well as mixtures thereof
  • the mixture press-moulded to bond and shape the mixture into the desired tool.
  • the so-called hot-pressing method the mixture is placed in a mould having the shape of the abrasive tool to be formed and pressed at high pressure and temperature to cause sintering of the sinterable material
  • the mixture is first pressed at high pressure into the desired tool shape and thereafter fired at high temperature in a furnace to sinter the tool.
  • Tools fabricated in this manner are commonly referred to as metal-bonded abrading or cutting tools
  • Efficiency and lifetime of an abrading or cutting tool are among others determined by the degree of uniformity of the distribution of the abrasive grains on the surface or volume of the tool and by the retention strength of the abrasive grains within the surrounding matrix material.
  • the difficulty of uniformly distributing abrasive particles throughout the matrix material was first overcome by the method taught in US patent 3,779,726 .
  • This document proposes to tumble the abrasive grains in the presence of a powder of sinterable material and binding agent while controlled amounts of water are simultaneously sprayed thereon. In this way, each abrasive particle is singularly coated with a sinterable particulate mass in such a way that granules, so-called "pellets", are formed.
  • a granule for use in the production of abrasive or cutting tools comprises a single abrasive grain surrounded with a sinterable particulate mass, which comprises particles of sinterable material (e.g. fused tungsten carbide powder, sintered tungsten carbide cobalt or any other suitable sinterable material), binding agent and solvent for the binding agent.
  • sinterable material e.g. fused tungsten carbide powder, sintered tungsten carbide cobalt or any other suitable sinterable material
  • binding agent dissolved by the solvent is of colloidal consistency.
  • the dissolved binding agent renders the granule malleable.
  • plasticity is used, in the context of the present disclosure to designate a consistency corresponding approximately to that of modelling clay, which facilitates the manufacture of abrasive tools. For instance, after the granules have been introduced into a mould, they can be pressed together by relatively small amounts of pressure so that they are preliminarily fixed with respect to the mould. It is thus ascertained that the abrasive particles remain in place when additional matrix material is poured into the mould and when the mixture is sintered.
  • Granules as described above are preferably made in a mixing container, such as e.g. a mixing drum, a mixing bowl or a fluidised bed apparatus, into which the abrasive grains are introduced. Particles of sinterable material and particles of binding agent along with a quantity of solvent for the binding agent are then progressively introduced into the mixing container and mixed with the abrasive grains.
  • the rates at which the different components are added to the mixture are controlled in such a way that the abrasive grains are singularly coated with the particles of sinterable material and the dissolved binding agent.
  • the addition of the particles of sinterable material has to occur at a rate that is sufficiently low so that they do not adhere on themselves but rather on the abrasive grains.
  • the particles of sinterable material and the particles of binding agent powder are advantageously mixed in the desired proportions prior to introduction into the mixing container.
  • the binding agent comprises a cellulose ether, e.g. methylcellulose and/or ethylcellulose.
  • the solvent for the binding agent preferably comprises an organic solvent.
  • Glycerol formal is presently regarded as particularly suited solvent, e.g. with methylcellulose and/or ethylcellulose as binding agent.
  • the combinations of these components are chemically inert with respect to the particles of sinterable material and the abrasive particles.
  • the solvent and the binding agent are advantageously substantially water-free, as the presence of water in the mixture could cause oxidation of metallic particles.
  • Glycerol formal has furthermore the advantage of an elevated boiling point (191-195°C at normal atmospheric pressure), which is a highly preferred property of a solvent for the binding agent. Consequently, at room temperature, glycerol formal is much less volatile than for instance ethanol. The low volatility of the solvent ascertains that the malleability of the granules is stable in time and that such granules can be stored substantially longer than conventional granules without drying and becoming brittle.
  • the binding agent/solvent combination is preferably chosen so that they completely vanish during the high-temperature treatment substantially without leaving any organic residue behind in the matrix.
  • Methylcellulose, ethylcellulose and glycerol formal evaporate easily at temperatures above 500-600°C.
  • the abrasive grains of the granules can e.g. be diamonds (natural or synthetic ones).
  • the diamonds may have a coating, e.g. provided in a CVD (chemical vapour deposition) step, which can achieve higher retention strength in the matrix material.
  • the abrasive grain comprises a diamond surrounded with a sintered or fused coating.
  • such an abrasive grain may be obtained by subjecting diamonds (CVD-coated or not) to a treatment as described above, thereby providing granules, which are subsequently heat-treated so as to harden the coating. These heat-treated granules are then used as abrasive grains in a further coating step.
  • Such granules are thus provided with a hard inner coating and a malleable outer coating.
  • the malleable outer coating provides for eased handling of the encapsulated diamonds in the production of a tool, whereas the hard inner coating provides for enhanced retention of the diamonds in the matrix of sintered material. Additionally, the hard inner coating ensures that after pressing the granules into the mould, the abrasive grains remain spaced from one another by a distance of at least twice the thickness of the inner coatings, which favours a still more homogeneous distribution of the abrasive grains in the matrix. It should not be forgotten either that, during the pressing of the green, the inner coating prevents the abrasive grains from coming into direct contact with the mould and cause scratches.
  • a sinterable particulate paste for the production of abrading or cutting tools comprising abrasive grains
  • the sinterable particulate paste comprises particles of sinterable material (e.g. fused tungsten carbide powder, sintered tungsten carbide cobalt or any other suitable sinterable material), binding agent and solvent for the binding agent.
  • the binding agent preferably comprises a cellulose ether, most preferably methylcellulose and/or ethylcellulose.
  • the solvent for the binding agent preferably comprises an organic solvent, most preferably glycerol formal. The consistency of the paste can vary depending on the proportions of the binding agent and the solvent.
  • methylcellulose and/or ethylcellulose as binding agent and glycerol formal as solvent are generally those mentioned above with respect to the granules: (a) rapid dissolution of the binding agent at room temperatures, (b) chemical inertness with respect to the particles of sinterable material and the abrasive particles, in particular no oxidation of metallic particles, (c) lasting consistency of the paste due to the low volatility of the solvent, (d) residue-free vanishing of the binding agent/solvent during the high-temperature treatment.
  • the abrasive grains may e.g. be CVD-coated or uncoated diamonds (natural or synthetic ones).
  • the abrasive grain comprises a diamond surrounded with a sintered or fused coating, which ensures that the abrasive grains remain spaced from one another within the paste by a distance of at least twice the thickness of the inner coatings.
  • Fabrication of a paste of sinterable material containing abrasive grains may be achieved in a simpler way than the production of malleable granules.
  • a preferred method for obtaining the sinterable paste one mixes the abrasive grains, the particles of sinterable material and the binding agent in the relative proportions and adds to the so-formed mixture an amount of solvent until the desired consistency of the paste is reached.
  • Fig. 1 schematically shows a granule 10 with a diamond 12 surrounded with a malleable sinterable particulate mass 14.
  • Granules 10 are e.g. produced as illustrated with respect to Fig. 2.
  • the diamonds 12, having particle sizes preferably above 180 ⁇ m, are fed into a rotary mixing container 16.
  • the amount of diamonds 12 and the rotational speed of the mixing container 16 are chosen such that the diamonds 12 roll on themselves under the action of gravity.
  • a mixture 18 of a powder of sinterable material and binding agent is progressively sifted onto the diamonds 12, while a fine spray 20 of solvent for the binding agent is directed thereto by nozzle 22.
  • the binding agent and the corresponding solvent are chosen so that wetting the powder of binding agent with the solvent yields a colloidal substance.
  • the powder of sinterable material consists of 30% by weight of CuMn powder and 70% by weight of fused tungsten carbide.
  • the grain size of the CuMn and the fused tungsten particles may e.g. range from 0.8 ⁇ m to 250 ⁇ m and even higher.
  • the powder of sinterable material consists of 50% by weight of fused tungsten carbide (particle size below 45 ⁇ m), 25% by weight of cobalt powder (particle size below 10 ⁇ m), 5% by weight of nickel powder (particle size below 10 ⁇ m) and 20% by weight of CuMn or bronze powder (particle size below 60 ⁇ m).
  • the powder of sinterable material consists of 30% by weight of iron powder (particle size approximately 12 ⁇ m?), 25% by weight of cobaliteTM (pre-alloy made of 10% Co / 20% Cu /70% Fe, (particle size below 20 ⁇ m)) powder, 25% by weight of irregular bronze powder (grade 85/15, particle size below 45 ⁇ m) and 20% by weight of nickel powder (particle size below 10 ⁇ m).
  • methylcellulose or ethylcellulose powder (particle size below 500 ⁇ m) is used as binding agent and glycerol formal as solvent.
  • the weight ratio of cellulose ether to sinterable material ranges from about 0.5 to 6%.
  • the proportion of glycerol formal with respect to the cellulose ether determines the degree of plasticity of the granules. It should be noted that by adding to the mixture a higher amount of cellulose ether (e.g. between 10 and 20% of the weight of the sinterable powder), and correspondingly a higher amount of solvent, one obtains a paste rather than individual granules.
  • the use of such a paste in particular a paste comprising abrasive grains with a hard coating, might even be preferred over the use of granules.
  • the paste can be made very sticky so that is shows very good adhesion to a mould, e.g. a graphite mould.
  • the rate of addition of solvent is kept low enough so that the diamonds do not adhere to each other.
  • the rate of addition of the powder mixture of sinterable particles and binding agent is kept low enough so that the particles of sinterable material do not agglomerate on themselves but rather on the diamonds.
  • Fig. 3 shows an example of a granule 30 with a diamond core 32, a hard inner coating 34 and a malleable outer coating 36.
  • the outer coating 36 is applied in a method as discussed with respect to Fig. 2, except that one uses previously coated diamond particles as seeds on which accumulates the malleable particulate mass.
  • the thicknesses of the different coatings 34, 36 may be chosen according to the desired application: the thickness of the inner coating 34 typically lies between 15 and 200 ⁇ m, the thickness of the outer coating 36 between 15 ⁇ m and 3 mm.
  • the inner coating 34 may be applied by any suitable method. However, it is considered particularly advantageous if encapsulation of diamonds 32 in respective inner coatings 34 is achieved by producing granules using the method described with reference to Fig. 2 and subsequently sintering these granules to harden the coating.
  • the powder of sinterable material chosen for the two coatings 34, 36 may be the same, so that compatibility issues are eliminated.
  • the inner coatings 34 of the double-coated diamond-core granules 30 may be produced using some other binding agent/solvent combination that is compatible with the intended outer coating. For instance, for the inner coating one could use one of the mixtures disclosed in US 3,316,073 e.g. with dextrin as binding agent water as solvent. After applying the inner coating layer 34 onto the diamond 32, the inner coating layer 34 is dried and sintered. The outer coating layer 36 is then applied onto the hardened inner coating 34.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Manufacturing & Machinery (AREA)
  • Materials Engineering (AREA)
  • Organic Chemistry (AREA)
  • Polishing Bodies And Polishing Tools (AREA)
EP06119978A 2006-09-01 2006-09-01 Granules pour l'utilisation dans les productions des outils abrasifs ou coupants Withdrawn EP1894983A1 (fr)

Priority Applications (10)

Application Number Priority Date Filing Date Title
EP06119978A EP1894983A1 (fr) 2006-09-01 2006-09-01 Granules pour l'utilisation dans les productions des outils abrasifs ou coupants
CA2660803A CA2660803C (fr) 2006-09-01 2007-08-31 Produit intermediaire s'utilisant pour la fabrication d'outils d'abrasion ou de coupe
AU2007291207A AU2007291207B2 (en) 2006-09-01 2007-08-31 Intermediate product for use in the production of abrading or cutting tools
US12/377,880 US20110056143A1 (en) 2006-09-01 2007-08-31 Intermediate product for use in the production of abrading or cutting tools
AT07820000T ATE467671T1 (de) 2006-09-01 2007-08-31 Zwischenprodukt für die herstellung für schleif- oder schneidwerkzeuge
PCT/EP2007/059103 WO2008025838A1 (fr) 2006-09-01 2007-08-31 Produit intermédiaire s'utilisant pour la fabrication d'outils d'abrasion ou de coupe
EP07820000A EP2057244B1 (fr) 2006-09-01 2007-08-31 Produit intermédiaire s'utilisant pour la fabrication d'outils d'abrasion ou de coupe
DE602007006512T DE602007006512D1 (de) 2006-09-01 2007-08-31 Zwischenprodukt für die herstellung für schleif- oder schneidwerkzeuge
PCT/EP2007/059101 WO2008025836A1 (fr) 2006-09-01 2007-08-31 Granulés pour une utilisation dans la production d'outils abrasifs ou coupants
CN200780032031.3A CN101511965B (zh) 2006-09-01 2007-08-31 用于制造研磨或切割工具的半制品

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
EP06119978A EP1894983A1 (fr) 2006-09-01 2006-09-01 Granules pour l'utilisation dans les productions des outils abrasifs ou coupants

Publications (1)

Publication Number Publication Date
EP1894983A1 true EP1894983A1 (fr) 2008-03-05

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EP06119978A Withdrawn EP1894983A1 (fr) 2006-09-01 2006-09-01 Granules pour l'utilisation dans les productions des outils abrasifs ou coupants

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EP (1) EP1894983A1 (fr)
CN (1) CN101511965B (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2013068469A1 (fr) 2011-11-09 2013-05-16 Element Six Limited Procédé de fabrication d'éléments de coupe
CN114012089A (zh) * 2020-10-20 2022-02-08 北京安泰钢研超硬材料制品有限责任公司 一种金刚石包裹球的制备方法及生成装置

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
TW201330982A (zh) * 2012-01-20 2013-08-01 Zhong-Yu Huang 研磨布改良製法
KR102536516B1 (ko) * 2015-03-06 2023-05-24 에이치. 비. 풀러, 컴퍼니 용매계 프라이머 조성물
PT3265500T (pt) * 2015-03-06 2019-04-15 Fuller H B Co Composição primária à base de água
CN106553136A (zh) * 2015-09-28 2017-04-05 河南工业大学 熔浸法制备金属结合剂金刚石砂轮
US10166634B2 (en) * 2016-12-09 2019-01-01 Caterpillar Inc. Laser cladding using flexible cord of hardfacing material with diamond
TWI799769B (zh) * 2020-12-18 2023-04-21 遠東科技大學 一種均質的金屬玻璃基鑽石工具之製作方法
CN114378731A (zh) * 2022-01-25 2022-04-22 长沙市萨普新材料有限公司 一种用于蓝宝石减薄的金刚石砂轮盘及其制备方法

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4770907A (en) * 1987-10-17 1988-09-13 Fuji Paudal Kabushiki Kaisha Method for forming metal-coated abrasive grain granules
EP0533443A1 (fr) * 1991-09-20 1993-03-24 General Electric Company Granules de diamant à deux couches
WO2004053013A2 (fr) * 2002-12-10 2004-06-24 Treibacher Schleifmittel Gmbh Produit abrasif presentant des caracteristiques d'abrasion ameliorees

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4770907A (en) * 1987-10-17 1988-09-13 Fuji Paudal Kabushiki Kaisha Method for forming metal-coated abrasive grain granules
EP0533443A1 (fr) * 1991-09-20 1993-03-24 General Electric Company Granules de diamant à deux couches
WO2004053013A2 (fr) * 2002-12-10 2004-06-24 Treibacher Schleifmittel Gmbh Produit abrasif presentant des caracteristiques d'abrasion ameliorees

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2013068469A1 (fr) 2011-11-09 2013-05-16 Element Six Limited Procédé de fabrication d'éléments de coupe
CN114012089A (zh) * 2020-10-20 2022-02-08 北京安泰钢研超硬材料制品有限责任公司 一种金刚石包裹球的制备方法及生成装置
CN114012089B (zh) * 2020-10-20 2023-10-10 北京安泰钢研超硬材料制品有限责任公司 一种金刚石包裹球的制备方法及生成装置

Also Published As

Publication number Publication date
CN101511965A (zh) 2009-08-19
CN101511965B (zh) 2012-12-12

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